/Engine/Source/Runtime/MeshDescription/Public/MeshDescription.h
Populates the passed array of VertexIDs with the vertices which form the polygon perimeter
template<typename Alloc> void GetPolygonVertices ( const [FPolygonID](API\Runtime\MeshDescription\FPolygonID) PolygonID, [TArray](API\Runtime\Core\Containers\TArray)< [FVertexID](API\Runtime\MeshDescription\FVertexID), Alloc > & OutVertexIDs ) const